The ability to engage the world through tactile sensing is prevalent in all organisms. In humans, touch is used to manipulate and categorize objects, react to stimuli, and to perceive and control the body. Creating an artificial system with this range of capabilities is a daunting task but an important one if robots are to operate in similar environments as humans. Therefore, tactile sensing is an active area of robotics research.
Creating an artificial tactile system is difficult for many reasons. For example, the sensors must cover a large range and be compliant with the surfaces with which they interact. Moreover, the spatiotemporal nature of tactile stimuli, as well as the noisy sensors and environments in which they operate, make the perception of touch a complex problem. To encode tactile signals in the nervous system, there is evidence for both a rate code and a temporal code. A rate code, in which information is carried by rate of neuronal activity, is simpler and less susceptible to noise. A temporal code, however, where information is carried by the temporal order and time intervals of neural activity, has a larger capacity for encoding patterns.